The invention relates generally to firearms, and, more particularly, to firearms including a bolt assembly which can be configured to eject spent cartridges in a desired direction suitable for the shooter of the firearm.
The position terms used in this patent, like xe2x80x9cfrontxe2x80x9d, xe2x80x9cbackxe2x80x9d, xe2x80x9ctopxe2x80x9d, xe2x80x9cbottomxe2x80x9d or the like always assume a weapon in the normal firing position; (i.e., a weapon position in which the center axis of the barrel of the weapon runs generally horizontally and the direction of firing points xe2x80x9cforwardxe2x80x9d away from the shooter). The same convention applies for the direction statements used herein (xe2x80x9cto the frontxe2x80x9d, xe2x80x9cupwardxe2x80x9d, xe2x80x9cleftwardxe2x80x9d, etc.).
Bolt assemblies for incorporation into a small arm are known. One such assembly is known from FR-A-2,215,600. Bolt assemblies are also known in which the bolt head has a radial pin that engages in a slider that serves as a curved guide (see, for example, DE-A-32 44 315 D2).
A similar bolt assembly is also known from CH-A-580 269. After shooting, the bolt assembly travels rearward and a claw-like extractor on the bolt surface extracts the empty cartridge casing from the barrel. Casing ejection is then produced by the ejector, which strikes against the cartridge casing bottom during return of the bolt assembly. The cartridge is tilted laterally by the extractor and ejected through an opening in the weapon housing. The position of the bolt assembly can be varied for right or left ejection.
In simply configured automatic weapons, for example, in the Soviet assault rifle AK-47 (Kalaschnikov), casing ejection is produced through a protrusion fixed on the housing. The bottom of the cartridge casing strikes against this protrusion during return of the bolt assembly.
The ejection process just described can also be produced manually by the shooter. This is necessary, for example, when a cartridge does not fire during the shooting process and is not automatically ejected. The shooter must then reload by hand, whereupon the still live cartridge is ejected. The term cartridge casing, as used herein, therefore does not refer merely to the spent casings, but also to the casings of live cartridges.
Present day semiautomatic weapons and submachine guns are generally designed only for right-hand use. In these weapons the casings, during firing, are ejected on the right side. A left-hand shooter, who fires the weapon from the left shoulder, therefore faces the hazard of being struck on the right arm by the ejected cartridge casings. This hazard represents a significant burden for the shooter and makes left-handed use of such a weapon problematical.
In small arms of the so-called bullpup design, the magazine and bolt assembly are positioned behind (instead of in front of) the trigger. The casing ejector arranged above the magazine is, therefore, situated next to or right in front of the face when the weapon is aimed. Ejected casings in a right-handed weapon would therefore fly directly against the head or into the face of a left-handed shooter. Therefore, firing with the left hand is extremely hazardous, if not impossible, in a bullpup-type weapon that ejects to the right since the shooter cannot properly aim the weapon, but, instead, is forced to keep the weapon forward, away from the body.
The problems just described make it clear why left-handed shooters in military service are forced to learn to use the right hand and right-handed weapons. Because of the desired standardization of equipment, no other weapons are often available. Weapons for left-handed use, however, can significantly improve security of firing and safe handling of the weapon among left-handed shooters.
Weapons have already long been known that have a casing ejector arranged in the center, so that the casings are ejected upward. An example of this is the US M1 Garand semiautomatic rifle. This type of cartridge ejector permits firing of the weapon from both shoulders. However, a shortcoming in this arrangement is that the shooter can easily be struck on the head by the ejected cartridges (for example, when shooting xe2x80x9cfrom the hipxe2x80x9d, or when individual casings are ejected incorrectly (i.e., obliquely to the rear)). For weapons of the bullpup design, a center cartridge ejector is unsuitable, since the casings, as described above, are ejected at the site at which the shooter positions his head against the weapon for aiming.
Small arms are also known that permit conversion from right to left ejection and vice versa. For example, the French assault rifle FAMAS, is a bullpup design weapon in which the extractor claw can be alternately mounted on either of two sites on the bolt surface, so that the empty casings are ejected to the right or to the left. The weapon housing has ejection shafts on both sides. The ejection shaft which is not being used is covered by a cheek protector. Another example of this approach is the Austrian bullpup rifle Steyr AUG, in which, as in the FAMAS, the extraction claw can be mounted on either side.
In the bolt mechanism mentioned in CH 580 269 A5, a conversion between right and left ejection is produced by switching the bolt head from one incorporation position to another.
In addition, another bolt assembly is known from DE-GM 18 58 576, in which an ejector is accommodated, in addition to an extractor.
Moreover, a bolt assembly constructed from a bolt carrier and bolt head is known from DE 28 12 732 B2, in which the bolt head has a radial pin that engages in a slot of the bolt carrier that serves as a slot guide.
In accordance with an aspect of the invention, a firearm is provided which is capable of selectively ejecting a spent cartridge in either a first direction or a second direction. The firearm comprises a bolt carrier defining a first hole and a second hole; a bolt head dimensioned to be at least partially received within the bolt carrier; and a pin sized to engage the bolt housing and the first hole to secure the bolt head in a first position relative to the bolt carrier and to engage the bolt housing and the second hole to secure the bolt head in a second position relative to the bolt carrier. The firearm is adapted to eject the spent cartridge in the first direction when the bolt carrier is in the first position and to eject the spent cartridge in the second direction when the bolt carrier is in the second position.